DB_File Version 1.805 1st Sep 2002 Copyright (c) 1995-2002 Paul Marquess. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. IMPORTANT NOTICE ================ If are using the locking technique described in older versions of DB_File, please read the section called "Locking: The Trouble with fd" in DB_File.pm immediately. The locking method has been found to be unsafe. You risk corrupting your data if you continue to use it. DESCRIPTION ----------- DB_File is a module which allows Perl programs to make use of the facilities provided by Berkeley DB version 1. (DB_File can be built version 2, 3 or 4 of Berkeley DB, but it will only support the 1.x features), If you want to make use of the new features available in Berkeley DB 2.x, 3.x or 4.x, use the Perl module BerkeleyDB instead. Berkeley DB is a C library which provides a consistent interface to a number of database formats. DB_File provides an interface to all three of the database types (hash, btree and recno) currently supported by Berkeley DB. For further details see the documentation included at the end of the file DB_File.pm. PREREQUISITES ------------- Before you can build DB_File you must have the following installed on your system: * Perl 5.004_05 or greater. * Berkeley DB. The official web site for Berkeley DB is http://www.sleepycat.com. The latest version of Berkeley DB is always available there. It is recommended that you use the most recent version available at the Sleepycat site. The one exception to this advice is where you want to use DB_File to access database files created by a third-party application, like Sendmail or Netscape. In these cases you must build DB_File with a compatible version of Berkeley DB. If you want to use Berkeley DB 2.x, you must have version 2.3.4 or greater. If you want to use Berkeley DB 3.x or 4.x, any version will do. For Berkeley DB 1.x, use either version 1.85 or 1.86. BUILDING THE MODULE ------------------- Assuming you have met all the prerequisites, building the module should be relatively straightforward. Step 1 : If you are running either Solaris 2.5 or HP-UX 10 and want to use Berkeley DB version 2, 3 or 4, read either the Solaris Notes or HP-UX Notes sections below. If you are running Linux please read the Linux Notes section before proceeding. Step 2 : Edit the file config.in to suit you local installation. Instructions are given in the file. Step 3 : Build and test the module using this sequence of commands: perl Makefile.PL make make test NOTE: If you have a very old version of Berkeley DB (i.e. pre 1.85), three of the tests in the recno test harness may fail (tests 51, 53 and 55). You can safely ignore the errors if you're never going to use the broken functionality (recno databases with a modified bval). Otherwise you'll have to upgrade your DB library. INSTALLATION ------------ make install TROUBLESHOOTING =============== Here are some of the common problems people encounter when building DB_File. Missing db.h or libdb.a ----------------------- If you get an error like this: cc -c -I/usr/local/include -Dbool=char -DHAS_BOOL -O2 -DVERSION=\"1.64\" -DXS_VERSION=\"1.64\" -fpic -I/usr/local/lib/perl5/i586-linux/5.00404/CORE -DmDB_Prefix_t=size_t -DmDB_Hash_t=u_int32_t DB_File.c DB_File.xs:101: db.h: No such file or directory or this: LD_RUN_PATH="/lib" cc -o blib/arch/auto/DB_File/DB_File.so -shared -L/usr/local/lib DB_File.o -L/usr/local/lib -ldb ld: cannot open -ldb: No such file or directory This symptom can imply: 1. You don't have Berkeley DB installed on your system at all. Solution: get & install Berkeley DB. 2. You do have Berkeley DB installed, but it isn't in a standard place. Solution: Edit config.in and set the LIB and INCLUDE variables to point to the directories where libdb.a and db.h are installed. Undefined symbol db_version --------------------------- DB_File seems to have built correctly, but you get an error like this when you run the test harness: $ make test PERL_DL_NONLAZY=1 /usr/bin/perl5.00404 -I./blib/arch -I./blib/lib -I/usr/local/lib/perl5/i586-linux/5.00404 -I/usr/local/lib/perl5 -e 'use Test::Harness qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t t/db-btree..........Can't load './blib/arch/auto/DB_File/DB_File.so' for module DB_File: ./blib/arch/auto/DB_File/DB_File.so: undefined symbol: db_version at /usr/local/lib/perl5/i586-linux/5.00404/DynaLoader.pm line 166. at t/db-btree.t line 21 BEGIN failed--compilation aborted at t/db-btree.t line 21. dubious Test returned status 2 (wstat 512, 0x200) This error usually happens when you have both version 1 and version 2 of Berkeley DB installed on your system and DB_File attempts to build using the db.h for Berkeley DB version 2 and the version 1 library. Unfortunately the two versions aren't compatible with each other. The undefined symbol error is actually caused because Berkeley DB version 1 doesn't have the symbol db_version. Solution: Setting the LIB & INCLUDE variables in config.in to point to the correct directories can sometimes be enough to fix this problem. If that doesn't work the easiest way to fix the problem is to either delete or temporarily rename the copies of db.h and libdb.a that you don't want DB_File to use. Undefined symbol dbopen ----------------------- DB_File seems to have built correctly, but you get an error like this when you run the test harness: ... t/db-btree..........Can't load 'blib/arch/auto/DB_File/DB_File.so' for module DB_File: blib/arch/auto/DB_File/DB_File.so: undefined symbol: dbopen at /usr/local/lib/perl5/5.6.1/i586-linux/DynaLoader.pm line 206. at t/db-btree.t line 23 Compilation failed in require at t/db-btree.t line 23. ... This error usually happens when you have both version 1 and a more recent version of Berkeley DB installed on your system and DB_File attempts to build using the db.h for Berkeley DB version 1 and the newer version library. Unfortunately the two versions aren't compatible with each other. The undefined symbol error is actually caused because versions of Berkeley DB newer than version 1 doesn't have the symbol dbopen. Solution: Setting the LIB & INCLUDE variables in config.in to point to the correct directories can sometimes be enough to fix this problem. If that doesn't work the easiest way to fix the problem is to either delete or temporarily rename the copies of db.h and libdb.a that you don't want DB_File to use. Incompatible versions of db.h and libdb --------------------------------------- BerkeleyDB seems to have built correctly, but you get an error like this when you run the test harness: $ make test PERL_DL_NONLAZY=1 /home/paul/perl/install/bin/perl5.00560 -Iblib/arch -Iblib/lib -I/home/paul/perl/install/5.005_60/lib/5.00560/i586-linux -I/home/paul/perl/install/5.005_60/lib/5.00560 -e 'use Test::Harness qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t t/db-btree.......... DB_File needs compatible versions of libdb & db.h you have db.h version 2.3.7 and libdb version 2.7.5 BEGIN failed--compilation aborted at t/db-btree.t line 21. ... Another variation on the theme of having two versions of Berkeley DB on your system. Solution: Setting the LIB & INCLUDE variables in config.in to point to the correct directories can sometimes be enough to fix this problem. If that doesn't work the easiest way to fix the problem is to either delete or temporarily rename the copies of db.h and libdb.a that you don't want BerkeleyDB to use. If you are running Linux, please read the Linux Notes section below. Linux Notes ----------- Newer versions of Linux (e.g. RedHat 6, SuSe 6) ship with a C library that has version 2.x of Berkeley DB linked into it. This makes it difficult to build this module with anything other than the version of Berkeley DB that shipped with your Linux release. If you do try to use a different version of Berkeley DB you will most likely get the error described in the "Incompatible versions of db.h and libdb" section of this file. To make matters worse, prior to Perl 5.6.1, the perl binary itself *always* included the Berkeley DB library. If you want to use a newer version of Berkeley DB with this module, the easiest solution is to use Perl 5.6.1 (or better) and Berkeley DB 3.x (or better). There are two approaches you can use to get older versions of Perl to work with specific versions of Berkeley DB. Both have their advantages and disadvantages. The first approach will only work when you want to build a version of Perl older than 5.6.1 along with Berkeley DB 3.x. If you want to use Berkeley DB 2.x, you must use the next approach. This approach involves rebuilding your existing version of Perl after applying an unofficial patch. The "patches" directory in the this module's source distribution contains a number of patch files. There is one patch file for every stable version of Perl since 5.004. Apply the appropriate patch to your Perl source tree before re-building and installing Perl from scratch. For example, assuming you are in the top-level source directory for Perl 5.6.0, the command below will apply the necessary patch. Remember to replace the path shown below with one that points to this module's patches directory. patch -p1 -N